Device for driving anchoring members

ABSTRACT

A device for driving anchoring members is formed of a housing enclosing an axially movable barrel with a bore therethrough and having a cartridge chamber at its rearward end. A plug axially movable through the housing is biased against the rear end of the barrel and forms a closure for the cartridge chamber. The barrel and the plug and the cross-sectional areas of the bore and the cartridge chamber are sized to afford a force locking connection between the barrel and the plug under the force of the explosive gases generated in the cartridge chamber.

United States Patent Inventors Wolfgang Bayer Schaan; Karl-Ernst Udert, Triesen, Liechtenstein Appl. No. 758,095 Filed Sept. 6, 1968 Patented Jan. 19, 1971 Assignee I-Iilti Aktiengesellschaft Schaan, Liechtenstein Priority Oct. 2, 1967 Germany 1,603,843

DEVICE FOR DRIVING ANCHORING MEMBERS 2 Claims, 5 Drawing Figs.

US. Cl 227/10 Ill!- Cl B256 1/14 Field of Search 227/8, 9, I0, I 1

a [56] References Cited UNITED STATES PATENTS 3,168,744 2/1965 Kuavle 227/10X 3,172,119 3/1965 Siddons 227/10X 3 ,469,504 9/1969 Neighorn 227/ 10X Primary Examiner-Granville Y. Custer, Jr. Att0rneyMCGlew and Toren .9 11121 aa'razznznsnnnszu second housing part 2 by means ofa pivot pin 4 which extends in parallel relationship with the axis of the open space extending through the housing, or to put it another way, in parallel relationship with the axis of the firing direction from the device. The pin 4 extends rearwardly into the housing part 2 immediately above the handle part 3 and is secured against rotation by a stud 5.

Secured in threaded engagement within the muzzle end of the first housing part I is a protective cap 6 which extends forwardly from the muzzle end and contains a guide insert 7 having an opening for receiving anchoring members 8 to be driven from the device. Within the first housing part I and extending from its rearward end to the protective cap 6 is a barrel 12 which forms an axially extending bore 11 in the align ment with the opening through the guide insert 7. Disposed within the bore 11 is a hammer piston 9, see FIG. 1, which extends from the rearward end of the bore into the rearward end of the guide insert 7. At its rearward end, the hammer piston 9 has an enlarged head portion 9a which is in surface contact with the bore through the barrel while its forward end has a smaller diameter and is fitted into surface engagement with the opening through the guide insert 7. At the rearward end of the barrel, in axial alignment with the bore, is a cartridge chamber 13 having a passageway 13a communicating between the chamber and the bore. As a result of the passageway 13a, an annular surface Ila defines the effective surface area of the barrel 12 at the rearward end of the bore 11.

Within the open space through the second housing part 2 is a breech block which is biased by means of a spring 14 against the rearward end of the barrel l2. Secured within the breech block 15 is a firing pin 16 disposed in parallel relationship with the axis of the bore and arranged to contact the base of a cartridge disposed within the cartridge chamber 13 in the barrel 12. At its forward end, the firing pin 16 is supported in a replaceable insert 22 fitted within the breech block 15, and it extends rearwardly into a hole 21 formed in breech block 15. The replaceable insert 22 provides a closure for the rearward end of the cartridge chamber 13. Aligned behind the hole 21 and the breech block 15 is a pin-shaped guide member 18 which provides a support for the forward end of the spring 14. A reversing plate 17 is guided within a slot 23 located below the plug 22 and pivots about a pin 24. The reversing plate 17 extends upwardly within the hole 21, and its surfaces 17a and 1711 are arranged to be placed in positive connection with the rearward end of the firing pin 16. In FIG. I the device is shown in a starting position with the surface 170 of the reversing plate 17 resting on a cam 25a and with its surface 17a directed against the flange at the rearward end of the firing pin 16 and urging it toward the rear.

Disposed below the breech block 15, in the handle part 3 of the device, is a trigger 26 arranged to pivot about a pin 27. A lever 30 is secured to the trigger by means of pin 29 and is arranged in positive engagement with a striker pin 31 extending upwardly through the handle part and terminating immediately below the open space through the housing containing the reversing plate 17. Within the handle part the striker pin is guided and is pushed downwardly by a spring 32 against a second spring 33 which serves to cock the striker pin. At the bottom of the handle part 3, a screw 34 retains the second spring 33 in position.

As shown in FIG. I, a cam collar 35 is rotatably mounted on pin 4 at the rearward end of the first housing part 1. The cam collar 35 has a groove 35a which is engaged by a cam 25b of cam collar 25, mounted on the forward end of the second housing part 2, see FIG. 2. The cam 25b, engaged within the groove 35a, provides a stop for the pivoting motion of the front housing part 1 relative to the second housing part 2.

In FIG. 3 a cartridge 36 is shown within the cartridge chamber 13, and it can be ejected by a mechanism consisting ofa pivoting arm 37 and an ejector 38. The forward end of the pivoting arm 37 is secured by means ofa pin 40 within a recess 39 in the first housing part I and is arranged to pivot about the pin 40. The arm 37 extends rearwardly from the recess 39 into a recess 41 located in the second housing part 2, note FIGS. 2 and 4. The ejector 38 is mounted within the barrel 12 to pivot about pin 42 which is loaded by a spring 43 and keeps the ejector in the position shown in FIG. 3.

As illustrated in FIG. 4, the first housing part 1 is secured to the second housing part 2 by means of a spring-loaded ball 44 fitted within a recess in first housing part 1 and arranged to interengage in a corresponding recess 45 in the second housing part 2. Additionally, the first housing part I is secured in place by means of the pivoting arm 37 located within the recesses 39 and 41 of the first and second housing parts 1 and 2.

In FIG. 5 a portion of the device containing the hammer piston 9 in the rearward end of the bore 11, the cartridge chamber 13. and the breech block 15 are shown in a schematic arrangement to illustrate the relative areas acted upon by the forces F1, F2, generated by a cartridge exploded within the chamber 13. The following is an explanation of the manner in which the device operates.

Initially, with the device in the closed position, as shown in FIG. 1, the arm 37 is pivoted about pin 40 outwardly in the direction of the arrowf, and thereby permits a pivoting motion of the first housing part I about the pin 4 moving relative to the second housing part 2. In this position, when the housing part I is pivoted away from housing part 2, the barrel 12 is contained wholly within the first housing part 1. With the first housing part 1 opened, a cartridge 36 can be inserted into the cartridge chamber 13 and the housing part pivoted back into the closed position and the arm 37 pivoted back to its initial position opposite to the direction of the arrow f. With the cartridge loaded in the chamber 13, a nail or stud 8 is introduced into the muzzle end of the device, being inserted into the opening in guide insert 7 and being pushed rearwardly by hand operated means, such as a rod, until the head portion of the anchoring member contacts the forward end of the hammer piston 9 and urges its head portion 9a rearwardly within the bore into contact with the annular surface Ila at the rearward end of the bore.

With a cartridge 36 and an anchoring member 8 loaded in the device, the forward end of the guide insert is pressed against the target material and the insert 7 rides rearwardly, forcing the barrel 12 and the breech block 15 to move through the distance a within the open space within the housing parts 1 and 2, see FIG. 1. The rearward movement of the plug brings the device into the firing position in which the surface 170 of the reversing plate 17 is lifted from the cam 25a. The device is ready to be fired, and when the trigger 26 is pulled backwards, it urges the lever 30 against the striker pin, and the striker pin is released and jumps upwardly striking the bottom surface of the reversing plate 17 and causing its surface 17b to hit the rearward end of the firing pin 16, driving it forwardly against the base of the cartridge 36 and causing the cartridge to explode. The force of the gas generated when the cartridge is exploded acts against the hammer piston head 9a driving the piston through the bore and through the opening in the guide insert 7 and thereby driving the anchoring mechanism into the target material.

When the cartridge explodes, a gas pressure is developed which is uniform in all directions and, in proportion to the cross-sectional area A1, exerts a driving force F1 on the head portion 9a of the hammer piston 9. Since the driving force and the reaction force are of the same magnitude, a reaction force F2 is established of equal and opposite magnitude to the driving force Fl. In FIG. 5 it will be noted that the reaction force F2 is split into two components, the component F2 which is proportional to the annular area 11a at the end of the bore and acting in the rearward direction against the barrel l2 and the component F2 which is proportional to the largest cross-sectional area A2 within the cartridge chamber 13 and as a result, acts against the breech block 15 which by means of the replaceable insert 22, forms a closure at the base or rearward end of the cartridge chamber. If the annular area and the crosssectional area A2 are of the same size, then the two components of force, F2 and F2", are also of the same magnitude.

and F2", they move in the direction away from the muzzle end of the device, that is, toward its rearward end and can be utilized to dampen the reaction force F2 within the device. For example, if the annular area Ila which forms the end of the bore within the barrel is equal to the cross-sectional area A2 within the cartridge magazine, and if the mass of the barrel l2 and the mass of the breech block are identical. then the breech block 15 and the barrel 12 are accelerated at the same rate by the equal forces F2 and F2", and as a result, a forcelocking connection is effected between these two parts during their movement toward the rearward end of the device, Such a force-locking connection obviates the need for expensive locking mechanisms for securing the two parts together. Naturally, the annular area lla at the end of the bore in the barrel may be larger than the cross-sectional area A2 within the cartridge magazine and balancing of the acceleration forces can be achieved by correspondingly dimensioning the masses of the plug and the barrel. a

After the anchoring member has been inserted, the device can be removed from the target material. Next, the arm 37 is pivoted out of its normal operating position, shown in FIG. 3, and it moves in the direction of the arrow f, then the first housing part is pivoted about the pin 4 out of alignment with the second housing part until it reaches the stop formed by the cam 25b. With the housing parts 1, 2 pivoted apart, by pushing Y the arm 37 further in the direction of arrow f, the arm 38b of the ejector 38 is pushed in the direction of the cartridge chamber 13, and as it pivots about the pin 42, the arm 38a ejects the spent cartridge casing from the cartridge chamber and the device is now ready to be reloaded for another cycle of anchor insertion.

We claim: 1. A device for driving anchoring members into a hard target material such as iron, concrete, and the like, wherein the device comprises a housing, said housing comprising a first part and a second part in axial alignment and forming an axially extending open space extending through said first part and said second part, said first part forming the muzzle end of said housing and said second part forming the rearward end of said housing, means for pivoting said first part relative to said second part about an axis parallel to the axis of the open space stantially smaller than the cross-sectional area of said bore in said barrel, a breech block positioned in the second part of said housing and within the open space through said housing rearwardly of said barrel and arranged to form a closure for the rearward end of said cartridge chamber, means disposed within said second part of said housing and adapted to discharge a cartridge positioned within said cartridge chamber within said barrel, resilient means disposed within the rearward end of said open space in said second part of said housing in contact with the rearward end of said breech block for biasing said breech block against the rearward end of said barrel and said cartridge chamber, a protective cover is fitted within and extends axiallyfrom themuzzle end of said housing, a guide insert is positioned within said protective cover and has an opening therethrough in axialalignment with the bore through said barrel, and said guide insert being adapted to receive an anchoring member in its opening and being arranged to slide rearwardly within said housing a predetermined distance along with said barrel and block when the for+ ward end of said guide insert is pressed against a target material, a hammer piston is disposed within the bore in said barrel,

said hammer piston comprises a head portion having a larger diameter than a longitudinally extending shank portion which extends therefrom toward the muzzle end of said barrel, said head portion being arranged to fit in contacting relationship with the surface of the bore within said barrel and the forward end of said shank portion being arranged to fit within and in contacting relationship with the opening through said guide insert, said barrel has an annular surface forming the rearward end of said bore, said annular surface encircling the opening between said bore and said cartridge chamber, said means for pivoting said first part of said housing relative to said second part thereof comprising a pin affixed within said second part of said housing and extending forwardly therefrom in parallel relationship with the axis of the open space through said housing toward the muzzle end of said housing, said first part of said housing pivotally mounted on said pin, means mounted on said pin adjacent the interface of said first and second parts of said housing for forming a stop for the pivotal motion of said first part relative to said second part, said means adapted to discharge a cartridge comprising a firing pin mounted in said breech block aligned rearwardly of said cartridge chamber, a latch member pivotally mounted within said second part of said housing having a first surface for engagement with said firing pin for preventing said firing pin from riding forwardly toward said cartridge chamber, and a second surface arranged to strike said firing pin at its rearward end and to drive said firing pin against the base of said cartridge chamber, a striker pin arranged for movement into engagement with said latch member to direct said latch member against said firing pin for driving said firing pin toward said cartridge chamber, and a trigger arranged to release said striker pin for movement against said latch member.

2. A device as set forth in claim 1, wherein said breech block contains a replaceable insert aligned rearwardly of and forming a closure for the base of said cartridge chamber, said replaceable insert having an opening therethrough supporting the forward end of said firing pin. 

1. A device for driving anchoring members into a hard target material such as iron, concrete, and the like, wherein the device comprises a housing, saId housing comprising a first part and a second part in axial alignment and forming an axially extending open space extending through said first part and said second part, said first part forming the muzzle end of said housing and said second part forming the rearward end of said housing, means for pivoting said first part relative to said second part about an axis parallel to the axis of the open space through said housing, a barrel positioned within and axially movable through the open space in said housing and being axially movable within the first and second parts of said housing, said barrel having an axially extending bore therethrough open at its opposite ends, said barrel forming a cartridge chamber aligned with and having an opening communicating with the end of the bore opposite the muzzle end of said barrel, said cartridge chamber having a crosssectional area substantially smaller than the cross-sectional area of said bore in said barrel, a breech block positioned in the second part of said housing and within the open space through said housing rearwardly of said barrel and arranged to form a closure for the rearward end of said cartridge chamber, means disposed within said second part of said housing and adapted to discharge a cartridge positioned within said cartridge chamber within said barrel, resilient means disposed within the rearward end of said open space in said second part of said housing in contact with the rearward end of said breech block for biasing said breech block against the rearward end of said barrel and said cartridge chamber, a protective cover is fitted within and extends axially from the muzzle end of said housing, a guide insert is positioned within said protective cover and has an opening therethrough in axial alignment with the bore through said barrel, and said guide insert being adapted to receive an anchoring member in its opening and being arranged to slide rearwardly within said housing a predetermined distance along with said barrel and block when the forward end of said guide insert is pressed against a target material, a hammer piston is disposed within the bore in said barrel, said hammer piston comprises a head portion having a larger diameter than a longitudinally extending shank portion which extends therefrom toward the muzzle end of said barrel, said head portion being arranged to fit in contacting relationship with the surface of the bore within said barrel and the forward end of said shank portion being arranged to fit within and in contacting relationship with the opening through said guide insert, said barrel has an annular surface forming the rearward end of said bore, said annular surface encircling the opening between said bore and said cartridge chamber, said means for pivoting said first part of said housing relative to said second part thereof comprising a pin affixed within said second part of said housing and extending forwardly therefrom in parallel relationship with the axis of the open space through said housing toward the muzzle end of said housing, said first part of said housing pivotally mounted on said pin, means mounted on said pin adjacent the interface of said first and second parts of said housing for forming a stop for the pivotal motion of said first part relative to said second part, said means adapted to discharge a cartridge comprising a firing pin mounted in said breech block aligned rearwardly of said cartridge chamber, a latch member pivotally mounted within said second part of said housing having a first surface for engagement with said firing pin for preventing said firing pin from riding forwardly toward said cartridge chamber, and a second surface arranged to strike said firing pin at its rearward end and to drive said firing pin against the base of said cartridge chamber, a striker pin arranged for movement into engagement with said latch member to direct said latch member against said firing pin for driving said firing pin toward said cartridge chamber, and a trigger arranged to release said striker pin for movement against said latch member.
 2. A device as set forth in claim 1, wherein said breech block contains a replaceable insert aligned rearwardly of and forming a closure for the base of said cartridge chamber, said replaceable insert having an opening therethrough supporting the forward end of said firing pin. 